Mixed-function oxygenase system components and antioxidant enzymes in different marine bivalves: Its relation with contaminant body burdens

13 pages, 1 figure, 4 tablesA comparative study on the presence of the Mixed-Function Oxygenase (MFO) system components (cytochrome P450, cytochrome b5 and NADPH-cytochrome c (P450) reductase) and antioxidant enzymes (catalase, superoxide dismutase (SOD), glutathione peroxidase (GPX) and DT-diaphorase) has been carried out in four bivalve species: mussel, Mytilus galloprovincialis; oyster, Ostrea edulis; western oyster, Crassostrea gigas; and clam, Tapes semidecussata. The tissular concentrations of certain organic pollutants (e.g. PAHs, PCBs, DDTs, hexachlorobenzene and lindane) have been determined and the qualitative and quantitative differences in their bioconcentration patterns assessed. In general, cytochrome P450 content, NADPH-cytochrome c (P450) reductase and microsomal NAD(P)H-dependent DT-diaphorase activities correlated well with tissular PAHs concentrations, whereas a certain correlation between glutathione peroxidase (GPX) activity and organochlorinated compounds accumulation was also detecte